The energy for a power supply of a motor vehicle is, in general, made available by a generator driven by the internal combustion engine of the motor vehicle and by a power supply battery which is loaded by the generator and makes energy available to a plurality of electric consumers in the vehicle for ensuring the operation safety thereof. With the progressive development of the vehicle technology, in particular, the number and energy requirement of electric and electronic components of the vehicle also considerably increases. Electric consumers play a continuously increasing part having a power need that is comparatively high, but that occasionally persists only for a relatively short time interval.
DE 198 59 036 A1 has disclosed a power supply for a motor vehicle having only one primary system consisting of one generator, one power-supply battery and at least one consumer and one secondary system having one DC/DC converter and one capacitor which is loaded or unloaded according to the operating state of the motor vehicle.
With such a solution, support of the primary system of the power supply is achieved in the sense that in case of unfavorable operating conditions the energy stored in the capacitor can be made available again to the consumers situated in the primary system of the power supply. The energy of the primary system is supplied unspecifically with regard to those consumers having different power requirement.
The problem on which the invention is based is to further develop a switching system for making energy available to electric consumers in a manner such that even in case of high momentary power requirement of electric consumers a significant power load to a great extent does not occur.